McLaren is continuing to tease its new 2015 McLaren 675 LT, aka the Longtail. And in perfect timing to spite its Modenese rival Ferrari, which yesterday unveiled the glorious-looking 488 GTB, Woking has today confirmed new spec details of its uprated supercar.

McLaren continues to dripfeed small nuggets every week across its social media channels, and today's new photograph is the back end of the 675 LT laced in snow and an outrageous sound track (see video at foot of the page).

In January 2015, McLaren first showed a camouflaged 675 LT prototype wearing the iconic 41 numbered livery from the F1 sports car, a nudge-nudge, wink-wink that the Longtail name could make a reappearance.

And at the 2015 Geneva motor show, that tip will become a reality when the 675 LT launches with a new aero package that delivers 40% more downforce. Perfect to key the Longtail harder into the tarmac.

McLaren 675 LT: what we know so far

This new road-legal racer will form the centrepiece on McLaren’s stand at the 2015 Geneva motor show. It is the spiritual successor to the F1 GTR Longtail, campaigned by the company so successfully in the late 1990s.

That 675 name points to the output in metric horsepower, or ps, so there’s a usefully devilish 666bhp to play with, Woking has confirmed. And now we know it's going to develop 516lb ft of torque (a stout 700 Newton metres) from its twin-turbocharged 3.8-litre V8.

It’s not just more power: there’s extra aero to create the extra downforce (though no details yet), new lightweight V8 components including new turbos, a trick titanium exhaust and less weight. Sounds like a pretty extreme 650 upgrade to us.

When can I buy a Longtail?

Sales start later in 2015; it will only be available as a coupe and it will be a road-legal member of the burgeoning McLaren Super Series range of cars, sitting alongside the 650S and Asia-only 625C.

They in turn sit above the forthcoming Sports Series of cheaper cars; think 911 rivals - and these will be seen at the 2015 New York auto show this Easter.